<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On 27/04/2010, at 11:39 AM, Steven Heimann wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Tue, 2010-04-27 at 02:05 +0100, Paul Mullins wrote:<br><snip lots><br><blockquote type="cite">NOW ANOTHER WORD OF WARNING.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Only licensed people should play around with 240 volts mains, this is what<br></blockquote><blockquote type="cite">the law states, if you are competed I think that's the right word, you could<br></blockquote><blockquote type="cite">make a great earthing system, ALSO you need to keep the two system apart<br></blockquote><blockquote type="cite">easy said. Also beware of potential voltage differences on the two earthing<br></blockquote><blockquote type="cite">systems, As I said my RF earth is better than my mains earth, so be aware .<br></blockquote><blockquote type="cite"><br></blockquote></snip><br><br>I would think that keeping the two earths separate creates a danger.<br>The two earths will be connected through the case of your expensive<br>radio gear. If a spike comes down the mains (wire gets hit by<br>lightning) these is a discharge path through your transceiver to the RF<br>earth which you have just said is better than your mains earth and thus<br>is a very attractive path for all those electrons.<br><br>I am not sure what the best answer is, but creating the potential for a<br>potential difference between the two earths seems like a bad idea.</div></blockquote><br></div><div>Yeah ditto, we were taught that your RF, Audio, and Mains earth/grounds should *always* be bonded together.. Especially if you're running audio circuits between different electrical supply circuits.. It was amazing how much earth buzz would appear just running FOH amps off a different circuit (but still form the same switchboard!) as your mixing desk... Though that's going back 15 years now, maybe they're pushing something different now?</div><div><br></div><div>--DG</div><div><br></div><div><br></div><div><span class="Apple-style-span" style="font-size: 12px; ">Damien Gardner Jnr<br>VK2TDG. Dip EE. GradIEAust<br><a href="mailto:rendrag@rendrag.net">rendrag@rendrag.net</a> - <a href="http://www.rendrag.net/">http://www.rendrag.net/</a><br>--<br>We rode on the winds of the rising storm,<br> We ran to the sounds of thunder.<br>We danced among the lightning bolts,<br> and tore the world asunder</span></div></body></html>